<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>my css</title>
    <style>
        body {
            background-color: silver;
        }
        h1 {
            text-align: center;
            background-color: mediumpurple;
        }
    </style>
</head>
<body>
<h1>达内云计算 Cloud Computing</h1>
<div>达内云计算 Cloud Computing</div>
</body>
</html>